Move KeyIdentifier->KeyEvent conversion to src/ui/.

ui/base/events/key_identifier_conversion.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_EXTENSIONS_KEY_IDENTIFIER_CONVERSION_VIEWS_H_
-#define CHROME_BROWSER_EXTENSIONS_KEY_IDENTIFIER_CONVERSION_VIEWS_H_
-
-#include "ui/base/keycodes/keyboard_codes.h"
+#ifndef UI_BASE_EVENTS_KEY_IDENTIFIER_CONVERSION_H_
+#define UI_BASE_EVENTS_KEY_IDENTIFIER_CONVERSION_H_
 
 #include <string>
 
+#include "ui/base/ui_export.h"
+
 namespace ui {
+
 class KeyEvent;
-}
 
 // Convert a KeyIdentifer (see Section 6.3.3 here:
 // http://www.w3.org/TR/DOM-Level-3-Events/#keyset-keyidentifiers)
 // to a ui::KeyEvent.
-const ui::KeyEvent& KeyEventFromKeyIdentifier(
+// This should only be called from the UI thread.
+UI_EXPORT const ui::KeyEvent& KeyEventFromKeyIdentifier(
     const std::string& key_identifier);
 
-#endif  // CHROME_BROWSER_EXTENSIONS_KEY_IDENTIFIER_CONVERSION_VIEWS_H_
+}  // namespace ui
+
+#endif  // UI_BASE_EVENTS_KEY_IDENTIFIER_CONVERSION_H_